Diaryl neopentane compositions



several hours at room temperature.

Patented June 29, 1954 smrEs PATENT OFF-ICE 'DIARYL 'NEOPENTANECOMPOSITIONS Edward 'F. Rogers, Middletown, and Horace D.

Brown, 'Pl-ainfield, N. J assignors'to" Merck l:v

Jersey a corporation-of New No Drawing. Application February :16, 1950,Serial No. 144,591

-2 'Claims. 1

This invention relate's to the new chemical-com- ;pounds 1,1 bis(pmethylphenyl)--2,2-dimethy1 propane and 1;1-bis(p-'methoxyphenyl)-2,2-'dimethyl-propane and tothe process of preparing these compounds.It'is .also concerned'withthe preparation of certain novel chemicalcompounds, produced as intermediates in the synthesis of 1,1- bis(pmethylphenyl) -2,2-dimethyl-propane and 1,l-bis(p-methoxyphenyl)-2,2-dimethyl-propane. These intermediate compounds include1,1-bi's'(pmethylphenyl) -2,2-dimethy1-propanol-1, and 1,1-

and-a para methylor methoxy substituted phenyl Grignard reagent whichmay be identified by the following formula:

ll'lgBr wherein'R is a methyl or methoxy group.

The *alkyl ester of pivalic' acid maybe reacted with the Grignardreagent inaniether medium. The'reaction mixture is cooled duringthezaddition of the 'reactants'and thenis' allowed tost'andfor Themagnesium complex is decomposed with ammoniumchloridesdlution'and-thesolvent isrenioved. This '2 results'ina'compoundwhich' maybe identified by the following structuralformula:

R whereinthe-substituents R are the'same and are selected from thegroupconsisting .of methyl and methoxy.

Thediaryl-substituted neopentyl alcohols above are thenvhydrogenatedin-the presence of a copper chromite catalystto produce thecorresponding propane which has the formula:

WhereinR is asabove. That thishydrogenation couldf be carriedoutsuccessfully was entirely unexpected, in View of the highly hinderedcharacter of the moleculeand the known tendency of neopentylalcohols todehydrate and rearrange particularly at elevated temperatures.

Incarrying out thisnew hydrogenation process, it is preferred to reactthe propanol-derivative with'hydrogen at'atemperature of about PIE-275"C., .at a pressure in excess of about '200 atmos- 'p'her'es', 'in'th'epres'enceo'f about 5% by weight of copper chromite catalyst, and until 1molar equivalent of hydrogen has been consumed. A total reaction periodof about 3 hours is usually ample. The alcohol treated is preferably,though not necessarily, dissolved in a suitable solvent, such as a loweraliphatic alcohol. We further prefer the temperature range ZOO-250 C. Attemperatures below about 175 C., the reaction progresses too slowly tobe practicable. Above about 275 0., dehydration and rearrangement mayoccur.

The catalyst employed is prepared as described on p. 13 of Adkins,Reactions of Hydrogen with Organic Compounds over Copper-Chromium Oxideand Nickel Catalysts, The University of Wisconsin Press (1937). At theend of the reaction period, the catalyst is separated from the reactionmixture, the solvent is removed by evaporation, and the residue ispurified by distillation or by recrystallization from a suitablesolvent.

We have found that the 1,1-diaryl-2,2-dimethyl-propanes described abovepossess marked and effective insecticidal activity.- A remarkablefeature of these compounds is the relation between the tertiary alkylgroup joined to the central carbon atom and the insecticidal activity.Less highly branched alkyl groups, when substituted for the tertiaryalkyl group do not produce comparable insecticidal activity. Structuralisomers of the insecticidal compounds, such as Z-methyl- 3,3 bis(pmethoxyphenyl) -butane, and higher and lower homologs, such asl,1-bis(p-methoxyphenyl) -2-methyl propane, are ineffective. Also, wehave found that the tertiary alkyl group must be adjacent to thedi-aryl-substituted methenyl radical and that compounds containinginterven ing methylene radicals are ineffective. It further appears thatthe phenyl substituents must be para-substituted and that only arestricted number of radicals inthis position will provide effectiveinsecticidal compounds. It has been found, for example, thatl,l-diphenyl-2,2-dimethyl-propane and1,1-bis(pfluorophenyl)-2,2-dimethylpropane are ineffective.

We have also discovered that the propane derivatives described hereinmay be successfully incorporated in a suitable inert solvent or mixtureof solvents, or in a solid mixture, with or without other substances,such as wetting, disparsing and sticking agents. The compounds may beemployed in such compositions either as the sole toxic agent or incombination with other insecticides, such as pyrethrum, rotenone, coppersalts, etc,, or with fungicidal or bactericidal agents, to providecompositions useful for household and agricultural dusts and sprays,textile coating and impregnation, and the like. For example, we havefound that these new compounds are highly soluble in various hydrocarbonmixtures, in alcohols, in halogenated hydrocarbons, and the like, andthat these compounds may be dissolved in such liquids to providesolutions of enhanced utility. The new compounds may also be placed inaqueous suspension by dispersing organic solvent solutions of thecompounds in water. A very useful composition is obtained by mixing oneof the new compounds with an inert, finely divided, solid diluent orcarrier, such as bentonite, bole, talc, charcoal, pumice, calciumcarbonate, and the like. The insecticidal compound may be admixed in itsoriginal form or in solution. In the latter case, the solvent isexpelled to leave the inert solid coated and impregnated with theinsecticidal compound. The foregoing compositions possess excellentstability.

no reduction in activity being apparent even after long periods ofstorage, and are very effective in destroying injurious insects of allkinds, such as moths, mosquitos, flies, beetles, and others.

The preparation of our novel compounds possessing a pronouncedinsecticidal activity, and the novel intermediate chemical compoundsobtained during the course of the reactions by which they are securedmay be illustrated by the following specific examples. It should benoted, of course, that these examples are intended to be illustrative ofthe methods and procedures utilized in preparing these compounds, andthat they are not intended to be restrictive or to be regarded asembodying the only way in which our novel compounds can be formed andrecovered.

EXAMPLEI In a three-necked flask, fitted with a separatory funnel,reflux condenser and stirrer was placed magnesium turnings (1 mol). Amixture of p-bromotoluene (1 mol) and dry ether was run in and the flaskwarmed gently until the reaction became rapid. Stirring was then startedand additional p-bromotoluene and dry ether was run in at such a rate asto cause vigorous refluxing. When the p-bromotoluene addition wascomplete the whole was stirred.

The flask was then cooled by immersion in an ice bath, and ethylpivalate (0.5 mol) was added. The reaction mixture was stirred for threehours While maintaining the vessel in an ice bath. The mixture was thenallowed to stand for about fifteen hours at room temperature. When thereaction flask had again been cooled by the ice-salt bath, a previouslyprepared aqueous ammonium chloride solution was added and a pasty solidseparated. The ether layer was separated and dried with anhydrous sodiumsulfate. The solvent was removed by distillation, and distillation underreduced pressure resulted in the recovery ofl,1-bis(pmethylphenyl)-2,2-dimethylpropanol-l, having a boilin point of165- 171 C./1 m-m.

Analysis-Calculated for Ciel-I240: C, 85.04; H, 9.02. Found: C, 85.12;H, 9.02.

grams of 1,1-bis(p-methylphenyl) -2,2-dimethyl-propanol-l was dissolvedin ethanol and placed in a bomb, and 15 grams of bariLun-stabilizedcopper chromite catalyst was added. The mixture was treated withhydrogen at 6000 p. s. i. and 250 C. for three hours, the bomb wascooled and the catalyst was removed by filtration. The filtrate wasdistilled, and the fraction boiling at 144-145? C./1 mm. was collectedas product There was obtained 30 g. of 1,l-bis(p-methylphenyl)-2,2-dimethyl-propane.

Analysis.Calculated for Ciel-I24: C, 90.40; H, 9.59. Found: C, 90.60; H,9.43.

1,1 bis(p methy1phenyl)'- 2,2 dimethyl' ple 3 hereinafter disclosed.

EXAMPLE 2 v vacuo. .-A;a0l1ude orange-colored .rSOhd weighing 146 gramswas obtained. The solid was recrystallized from petroleum ether (BO-60C.) to ive 1,1 bis(p-methoxyphentyl) 2,2 .dimethyli 6 paper entitledEvaluating-liquid insecticides (Soap ;10, '85 (1934)).

-'Adults- :of the German, cockroach =(Blatella germanica (L.)) "or-softhe milkweed rbug (Onpropanol-lhaving a melting ;point chin-83 C. 5copeltus :fasciatus -=(=Dallas)) were :anaes'thetized,AnalysisP-Calculated for 0191313031 C, 75.97; with :carbon dioxide,fandz'measured' quantities of -11, 8.05. Found: C, 75.51; 11.7.84.acetone solution of the 'test *compoundwere [degrams of 1,1-bistpmethoxyphenylfl-diposited .on'their ventral'thoracicsurfaces.=Obmethyl-propanol-l wasdissolved in ethanol and servations of mortalitywere .made daily :up to placed in a bomb, and lo grams of barium-sta-'10 the end of 4 days. The results of tthese tests biliz'ed copperchromite catalyst was added. The are indicated in Tablelbelow.

, TABLE 1 Clothes Moth Carpet BeetIe Gockroacli I, MilkweedBug o d P- xi1 .'-1

ompmm' ce iit Eamage, :ce n t Damage, ggg i .Bercent g ggly .ee t' m ewere the Product of Example IPr opane, 1,1-bis 0.25 7.5 1.0 Li-7 2,i000.None 2, 000 30. (p-methylphenyl)-2,2-dimethyl. v Y I, I, iiiffif.gtiiiiffifiiiiittt" 6 2, thei 500 Propane,1,l-diphenyl-2,2-dimethy1 2.0 30.0 2.0 11.0 2, 000 2, 000 None. l?'r(iipantiii 1,1-bis(p-fluorophenyl)-2,2- 1.0 75.0 1.0 25.0 2,000 (1 2,00010.

me Propeliliel, l,1-bls(p-methoxypheny1)-2 2.0 7.2 1.0 7.5 2, 000 2,000None. M e tl ian i e;bis(p-methoxyphenyl) 2.0 300 2.0 15.0 2,000 2,000Do. Ethane, 1,1-bis(p-methoxyphenyl) 2.0 25.0 2.0 l5.0 1,600 2, 000 Do.But ane, 2-meth i-3,3-his -methox 2.0 30.o 2.0 30.0 2, 000 1,600 Do.misfit? Ill-bis(p-methoxyphenyl)-3,3- 2.0 25.o 2.0 15.0 2, 000 2, 000Do.

dimethyl.

mixture was treated with hydrogen at 6000 p. s. i. EXAMPLE 4 and 250 C.for three hours. At the end of this 1 1 bis( p methoxyphenyl) 2,2dimethylpenod' the bomb and the catalyst propane, produced as describedin Example 2, was removed by filtration. The solvent was rewas tested onflies as follows. moved fi cm the filtrate by concentrating to dryness,and 26 grams of a granular product re- Plate test mained. The granularsolid was recrysta1lized Using a test patterned on that described bysfiiveral tunes from petroleum ether to glVe Barber and Schmitt(Houseflies resistant to 1015(1) methoxyph'?nyl) 2,2 dlmzthyl 40 DDTresidual sprays, N. J. Agr. Exp. Sta. Bull. pane r a meltmg of 742(1948)), adults of the housefly, 5 days of AnaZyszs.-Calculated forC19H24O2. C, 80.24, age, were fin d f a 15 minute period on H, 8.51.Found. C, 80.47, H, 8.2 glass plates on which the insecticide hadbeen1,1 1915(1) methoxyphenyl) 2,2 m y deposited in the amount of 100- mgm.per square prolmne P found 9 Possess efiectlve foot. In 30 minutes afterinitial exposure, 42% sectidal activity as shown in Examples 3, 4 and fthe flie were paralyzed and at the end of 24F 5 herelfmfterdlsclosedhours, 100% of the flies were dead. EXAMPLE 3 Spray test 1insecticidal compounds Produced as r Adult flies in screen cages weresprayed with scrlbel ln'Examples 1 and 2 and several homologs 6different concentrations (0.253.0%) of insectiand one isomer of thecompound of Examp e 2 cide in refined petroleum distillate solution. Thewere tested for insectidal activity as follows: Sprays were applied in aspray tower similar to C t t and carpet beetle t t that described by N.A. Waters (Chemical control of insectsjPublication No. 20, p. 115, Amer.The e method employed i a descnped Assoc. Adv. Science (1943)) using 5seconds at by R. E. Heal in a paper entitled Evaluating 10 p S 1pressure to apply 19 m1 5 pray per protection of fabrics from clothesmoth and carcage of insects The toxicity curve estab t beetle attack (J.Econ. Ent 35 (2) 249-52 P6 4 lished by these tests indicated that theconcen- (19 tration of insecticide giving an L. D. 50 was Woolen fabricwas impregnated with acetone 4% solutions of the insecticides to giveknown con- EXAMPLE 5 centrations on the fabric. After evaporation of thesolvent, 10 larvae of the webbing clothes T liisectwldal compounds P cas moth (Tineola biselliella (Hum.)) or of the black b f 1n Examples 1and were subiected to a carpet beetle (Attagenus pz'ceus (O1iv.)) werelarvlclde test as follows! confined on weighed patches of the treatedfabric Three-day 01d f of the yellow-felfer for 2 weeks. After removalof the larvae the (1111130 (Aedes em/1m (L3) were placed 111 W t patcheswere again ejghed The 105s in weight, to which was added an acetonesolution of the of the fabric is indicated as damage, in Table test p ud in the a unt f 1% f th wat r. I 1 Weight loss greater t 10 is 7Observations of mortality were made in 24 hours. considered to beinadequate protection mortality was observed When and p. p. m.,respectively, of 1,1-bis(p-methylphenyl) cockroach and mdkweed bug tests2,2-dimethyl-propane and 1,1 bis (p methoxy- A The test method employedfollowed a prophenyl)-2,2-dimethyl-propane were present.

cedure of F. 0. Nelson et al.. as described in a It should be understoodthat various changes may be made in our process; as herein describedwithout affecting the improved results attained. Various changes inprocedure differing from those herein given as illustrative of thepreferred embodiments of our invention may be made without departingfrom the scope thereof. Accordingly, the scope of our invention is to bedetermined in accordance with the prior art and appended claims.

We claim:

1. The process-that comprises reacting 1,1-bis- (p methylphenyl) 2,2dimethyl propanol 1 with hydrogen in the presence of a copper chromitecatalyst and recovering 1,1-bis(p-methylphenyl) -2,2-dimethyl-propane.

2. The process that comprises reacting 1,1- bis(p methoxyphenyl) 2,2dimethyl propanol-l with hydrogen in the presence of a copper chromitecatalyst at 6000 pounds per square inch pressure and 250 C. andrecovering 1,1-bis(pmethoxyphenyl) -2,2-dimethyl-propane.

References (Jited in the file of this patent UNITED STATES PATENTS OTHERREFERENCES Bielstein, Band VI, First Supplement, page 495, Compound No.3 (1931), Springer, Berlin, Germany.

2. THE PROCESS THAT COMPRISES REACTING 1,1BIS(P - METHOXYPHENYL) - 2,2 -DIMETHYL - PROPANOL-1 WITH HYDROGEN IN THE PRESENCE OF A COPPER CHROMITECATALYST AT 6000 POUNDS PER SQUARE INCH PRESSURE AND 250* C. ANDRECOVERING 1,2-BIS(PMETHOXYPHENYL)-2,2-DIMETHYL-PROPANE.